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Alecsey [184]
2 years ago
15

Suppose you left your lawn mower out all winter, and it is very rusty. Of your 250,000J of work, only 100,000J go towards cuttin

g the lawn. What is the efficiency of the lawn mower now?
A 40%
B 0.4%
C 0.04%
D 4%

REMINDER: PLEASE SHOW YOUR WORK!!!
Physics
1 answer:
mihalych1998 [28]2 years ago
7 0
Efficiency  = 

                 (useful work you get out of it) / (work you put into it)

           =        (100,000 J)  /  (250,000 J) 

           =            0.4  =  40%    (choice-A)


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Then the frictional force can be calculated as

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From kinetic energy formula, the combined velocity of the car can be determined

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